Flood Risk Management Responsibilities
The responsibility for flood risk management lies with a number of organisations depending on the type of flood risk. The Flood and Water Management Act 2010 made Upper Tier and Unitary Authorities the Lead Local Flood Authority; as such Birmingham City Council is responsible for local flood risk from small watercourses and brooks, surface water runoff and groundwater. The Environment Agency is responsible for flood risk from larger rivers and the sea. Severn Trent Water is responsible for flood risk from sewers.
However, flood risk management is the responsibility of everyone, not solely the organisations identified by the Flood and Water Management Act 2010. No single body has the means to reduce all flood risk. Effective management will involve various bodies each with a range of relevant duties and powers together with individual householders and businesses.
Rivers flood when the amount of water in them exceeds the flow capacity of the channel. Most rivers have a natural floodplain into which the water spills in times of flood, however in an urban situation these floodplains have often been built on over time.
The Environment Agency has direct responsibility for designated Main Rivers including the River Tame, River Rea, River Cole (downstream of Formans Road), The Bourn, Bourn Brook, Wood Brook, Stonehouse Brook, Hawthorne Brook, Hockley Brook, Perry Brook, Plants Brook, Hatchford Brook and Westerley Brook.
Birmingham City Council has responsibility for all other rivers and watercourses which are termed ‘Ordinary Watercourses’, however many are the responsibility of land owners but the council has powers under the Land Drainage Act 1991 to regulate and enforce duties on land owners. In general the council works with landowners to maintain and improve watercourses.
Landowners who own land bounding upon a river or other body of water are, under common law, riparian owners. Riparian owners responsibilities include the maintenance of the bank and bed of that section of watercourse, in order to avoid any obstruction of flow in the watercourse. Find out more in 'Living On The Edge', a guide to owning a riverside property produced by the Environment Agency.
Surface Water Flooding
Surface water is rainwater which is on the surface of the ground and has not entered a watercourse, drainage system or sewer. Surface water flooding occurs where high rainfall exceeds the drainage capacity in an area. Surface water cannot then enter the system or infiltrate into the ground and the drainage network overflows, with manholes surcharging. It is more difficult to predict and pinpoint than river or coastal flooding.
One of the most obvious and immediate forms of surface water runoff is on the highway. Highway drainage is generally the responsibility of the local authority as the highway authority. In the case of Birmingham City Council, maintenance of highway drainage is undertaken by Amey, the Council’s Maintenance and Management Partner. Generally highways are drained by means of traditional gullies (drains) at the side of the road which drain to sewers or watercourse.
Sewer flooding occurs when sewers are overwhelmed by heavy rainfall or when they become blocked. The likelihood of flooding depends on the capacity of the local sewerage system.
Severn Trent Water is responsible for public sewers, with standards governed by the water regulator, Ofwat. These include surface water sewers into which most surface water drains and then on into sewage works. Other sewers take surface water to local brooks and watercourses.
Individual property and land owners have responsibility for their own piped drainage infrastructure. Where piped drainage becomes part of the general shared infrastructure it is generally adopted as public and becomes the responsibility of Severn Trent Water.
Groundwater flooding occurs when water levels in the ground rise above surface levels or into the basement of buildings. It is most likely to occur in areas underlain by permeable rocks, called aquifers. These can be extensive regional aquifers, such as chalk or sandstone; or may be more local sand or river gravels in valley bottoms underlain by less permeable rocks.
Under the Flood and Water Management Act 2010, Birmingham City Council is the management authority for local groundwater flood risk.